Excretion

Why excretion is important?

It is the last part of the life process where we will discuss about excretion process that plays a vital role to survive us on this living land. Breakdown the food to get energy is not enough to make our life possible on this Earth because we cannot live a long until we do not remove the waste products from our body.

What is the definition of excretion?

Definition: It is a biological process of removal of waste (Nitrogenous waste) and harmful product which is produces through the metabolic process.

There is misconception of excretion: Many students were confused with the thing that the waste which is removed during the digestion process is also a part of excretion but it is wrong. The thing which comes out with the urine are said to be the nitrogenous waste that comes out during excretion.
Thing to be purified in Excretion: Blood.
The Organs involved in this process: Two pairs of Kidney; Ureters; Urinary Bladder and Urethra.

Human Excretion system-Excretion

Main Organ: Kidney (Nephrons).

Structure of nephrons:

Structure of a nephron- excretion

Remember: When you see the nephron diagram it looks quite complicating but you only focus on the things that are needed to you. So, not be confused.
Nephron: It is fundamental part to the kidney.
Components: Bowman’s capsule; Glomerulus; tubular part of the nephron and collecting duct.

Formation of Urine:

Glomerulus is a part of nephron in bowman capsule where the blood capillaries are coiled in a bundle. As we know that the wall of the capillaries is very this so the waste material enter into the tube of nephrons.

You will notice that here only Waste materials are transferred and the lipids (Fat), protein and carbohydrates are in the blood. So there must be a Filtration is occurred and this filtration is known as ultrafiltration.

Re absorption:

Now all the waste is moving in the tubular part of the nephrons. But when ultra-filtration has occurred there is the chance that some Salt, Protein, Glucose and most amount of water are transferred into tube which are the vital things for our body. So, they must be absorbed.This absorption of these things is done in tubular part of the nephron as well as collecting duct.

Since the wastes come out in dissolved form so some amount of water is not absorbed.

The amount of water absorbed depends on the two factors:-

Amount of water in the blood:-

If there is excess water in the blood then more will come out with the wastes and vice-Verse.

Amount of waste:-

If there is excess waste in the blood then more will come out with the wastes and vice-Verse.

All the process is done and then the urine is sent to the ureter and then sends to storage site- Urinary bladder. It is stored until we urge to urinate.

We have discussed the excretion process where we deal with the confusion and the organs that achieve this process. So I think you understand this whole processes. But still you have any confusion then comment us below we are active for you for 24*7 hours.

Structure of nephrons: